Codeforces Round #394 (Div. 2) - A

题目链接：http://codeforces.com/contest/761/problem/A

题意：给定a个偶数，b个奇数，问是否能构成奇偶相间的阶梯。
思路：a和b相差小于等于1即可构造出来。特判 a=0,b=0.

import java.io.PrintWriter;
import java.util.*;

public class Main {
    public static final int MAXN=100000+5;
    public static int v[]=new int [MAXN];
    public static void main(String[] args) {
        Scanner cin = new Scanner(System.in);
        PrintWriter out = new PrintWriter(System.out);
        int n=cin.nextInt(),m=cin.nextInt();
        out.println(Math.max(n,m)-Math.min(n,m)<=1&&(n>0||m>0)?"YES":"NO");
        cin.close();
        out.flush();
    }
}